Dark-out light trap sizing and placement

All guides

Dark-out light traps: modules 24/36/48/60 in, fan-wall placement (not pad face), and notes on pressure and light control. Ratings confirmed on quotation.

This is a sizing and placement guide for light traps on dark-out poultry houses. It complements the shorter article — Why do dark-out poultry houses need light traps? — and the product page Light traps for dark-out poultry houses. Catalogue modules and materials are named there; this page focuses on where traps go, which module band to start from, and how trap resistance couples to fans.

“Static pressure management” in the title is the engineering topic. This public site does not publish light-reduction ratios, lux figures, or trap pressure-drop tables. Those figures belong on the written quotation. Face area is set on the quotation so trap resistance is in the same design as the fans.

Why dark-out houses need traps

A dark-out poultry house runs a lighting program. Daylight at the fan openings would break that program. Light traps pass ventilation air and block daylight at the exhaust-fan wall. They are baffled air paths (commonly vertical vanes). Material on this site is black PVC with UV inhibitor, or as quoted. Specified with the house — not a one-size kit.

Correct placement (fan wall, not pad face)

Specify traps at fan openings or on a false wall in front of the fans — not on the cooling-pad face. They are specified separately from exhaust fans and evaporative cooling pads. In a poultry house tunnel ventilation system, traps are added at the fan end on dark-out houses; pads stay on the inlet.

Catalogue module sizes

Module sizes on this site: 24×24 in · 36×36 in · 48×48 in · 60×60 in · custom to opening. Catalogue modules 24, 36, 48, and 60 inch can be supplied; custom openings are quoted to the house. Module sizes help you choose; face area is set on the quotation.

Selection comparison

Relative trends only. Ratings are confirmed on the quotation.

Dimension	Module size band	Airflow resistance	Light-control trend
Catalogue start	24 / 36 / 48 / 60 in square modules, or custom to opening	Larger face area for a given baffle depth generally lowers face velocity for the same house airflow — resistance still belongs on the quotation with the fans	Baffled paths block daylight while passing air; lux / light-reduction ratios are not published here
Placement	Fan openings or false wall in front of fans at the exhaust-fan wall. Not on the cooling-pad inlet face. Couples to fan type selection (see Box / Hammer-shutter / Cone guide) and pad-and-fan tunnel design.
Static-pressure coupling	Trap resistance is designed with the fans on the quotation — same system as pads and exhaust. This site publishes no Pa trap tables. Send fan size and count with the house brief.
Material	Black PVC with UV inhibitor, or as quoted. Cleaning: inspect and remove dust — a blocked trap acts as a blocked fan.

Decision tree before you email

Confirm dark-out (lighting program) and that traps are needed at the fan wall.
Place at fan openings or a false wall in front of fans — never on the pad face.
Start from catalogue modules 24 / 36 / 48 / 60 in, or name a custom opening.
Send house length/width, eave height, fan size and count, country — so face area and trap resistance can be set with the fans on the quotation.

FAQ

What is a light trap used for in a dark-out house?

Light traps pass ventilation air and block daylight at the exhaust-fan wall. They are specified at fan openings or on a false wall in front of the fans — not on the cooling-pad face.

Can I buy a standard-size light trap?

Yes. Catalogue modules 24, 36, 48, and 60 inch can be supplied. Custom openings are quoted to the house.

Dark-out light traps for poultry houses: sizing, placement, and static pressure management